Cytotoxic CD4⁺ T cells (CD4⁺ CTLs) represent a novel subset of T cells with cytotoxic effects. They recognize target cells in an antigen-specific manner, relying on class II major histocompatibility complex (MHC-II) interactions. CD4⁺ CTLs exert cytotoxic effects on target cells by secreting cytotoxic molecules such as granzymes, perforin, and granulysin. Recent studies have revealed their significant roles in various autoimmune diseases. This review focuses on the differentiation, phenotypic characteristics, and roles of CD4⁺ CTLs in different types of autoimmune disorders, aiming to provide new insights for the prevention and treatment of these diseases.
Humans ; Autoimmune Diseases/immunology* ; CD4-Positive T-Lymphocytes/immunology* ; Animals ; T-Lymphocytes, Cytotoxic/immunology* ; Perforin/immunology* ; Granzymes/immunology*

Objectives To investigate interleukin 36γ (IL-36γ) expression, and analyze the influence of IL-36γ to CD8⁺ T cell activity in chronic obstructive pulmonary diseases (COPD) patients with secondary fungal pneumonia. Methods Peripheral blood was collected from 47 COPD patients, 39 COPD patients with secondary fungal pneumonia, and 20 controls. Bronchial alveolar lavage fluid (BALF) was isolated from 27 COPD patients with secondary fungal pneumonia. CD8⁺ T cells were purified. The levels of four IL-36 isoforms in plasma and BALF were measured by enzyme linked immunosorbent assay (ELISA). CD8⁺ T cells were stimulated with recombinant human IL-36γ. The levels of interferon γ(IFN-γ), tumor necrosis factor α(TNF-α), perforin and granzyme B in the cultured supernatants were measured by ELISA. Recombinant human IL-36γ-stimulated CD8⁺ T cells were co-cultured with NCI-H1882 cells in either direct cell-to-cell contact or Transwell^TM manner. The levels of IFN-γ, TNF-α, and lactate dehydrogenase in the cultured supernatants were assessed. The percentage of target cell death was calculated. Results Plasma IL-36α, IL-36β, and IL-36γ levels were significantly elevated in both COPD group and COPD with secondary fungal pneumonia group compared with those in control group. However, only plasma IL-36γ level was higher in COPD with secondary fungal pneumonia group than that in COPD group [(200.11±99.95)pg/mL vs (53.03±87.18)pg/mL, P=0.023]. There was no remarkable difference in plasma IL-36 receptor antagonist level among three groups. IL-36γ level in BALF from infectious site was higher than that from non-infectious site in COPD with secondary fungal pneumonia group [(305.82±59.60)pg/mL vs (251.93±76.01)pg/mL, P=0.011]. IL-36γ stimulation enhanced IFN-γ, TNF-α, perforin and granzyme B secreted by CD8⁺ T cells. When IL-36γ-stimulated CD8⁺ T cells were directly mixed with NCI-H1882 cells for co-culture, the percentage of cell death was increased [(16.06±3.67)% vs (11.47±2.36)%, P=0.002]. When using Transwell^TM plate for non-contact co-culture, IL-36γ-stimulated CD8⁺ T cell-mediated death of NCI-H1882 cells showed no significant difference compared to that without stimulation [(4.77±0.78)% vs (4.99±0.92)%, P=0.554]. Conclusion IL-36γ level in plasma and infectious site is elevated in COPD patients with secondary fungal pneumonia, which enhances the cytotoxicity of CD8⁺ T cells in peripheral blood and infectious microenviroment.
Humans ; Pulmonary Disease, Chronic Obstructive/complications* ; CD8-Positive T-Lymphocytes/metabolism* ; Male ; Female ; Aged ; Middle Aged ; Interferon-gamma/metabolism* ; Interleukin-1/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Lung Diseases, Fungal/complications* ; Bronchoalveolar Lavage Fluid/chemistry* ; Perforin/metabolism* ; Pneumonia/immunology* ; Granzymes/metabolism*

Objective To investigate the differences of type 2 innate lymphocytes (ILC2) and interlukin 9 (IL-9) between chronic lymphocytic leukemia (CLL) patients and healthy controls, and to understand the effects of ILC2 on the function of regulatory T cells (Tregs), CD8⁺ T cells and CLL cells through IL-9. Methods Flow cytometry was used to detect the levels of ILC2 and Tregs in the peripheral blood of 45 newly diagnosed CLL patients and 24 healthy controls, and the expressions of granzyme B and perforin in CD8⁺ T cells in the peripheral blood of 28 patients and 15 healthy controls; ELISA was used to detect the level of IL-9 in the serum. ILC2 of patients and healthy controls was sorted by immunomagnetic beads and cultured separately, and the level of IL-9 in the culture supernatant was measured by ELISA. ILC2 sorted from CLL patients and healthy control-derived peripheral blood mononuclear cells(PBMCs) were co-cultured with the B cell leukemia MEC-1 cells, one group was supplemented with IL-9 antibody and the other group was not. After 72 hours of culture, the ratio of Tregs, programmed death 1 (PD-1), T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), cytotoxic T lymphocyte antigen 4 (CTLA-4) on Tregs, granzyme B and perforin in CD8⁺ T cells were measured by flow cytometry, IL-9 level of the culture supernatant was measured by ELISA, the apoptosis of MEC-1 cells was measured by Annexin V-PI. Results Compared with the healthy control group, the levels of ILC2, Tregs and IL-9 in the CLL group increased significantly. The levels of granzyme B and perforin in CD8⁺ T cells were positively correlated in the peripheral blood of CLL patients. Compared with the healthy control group, IL-9 levels in the supernatant of sorted ILC2 from CLL patients increased. In the anti-IL9 antibody group, the level of PD-1 and TIGIT on Tregs decreased, and the level of granzyme B in CD8⁺ T cells increased significantly. The level of IL-9 in the anti-IL9 antibody group decreased statistically. And MEC-1 cells showed increased early apoptotic rate in the anti-IL9 antibody group statistically. Conclusion In CLL, ILC2 affects CD8⁺ T cells and Tregs through IL-9, which weakens the anti-tumor effect of CD8⁺ T cells, enhances the immunosuppressive effect of Tregs, and plays a role in the occurrence and development of CLL disease.
Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/immunology* ; CD8-Positive T-Lymphocytes/immunology* ; T-Lymphocytes, Regulatory/immunology* ; Middle Aged ; Male ; Female ; Interleukin-9/blood* ; Aged ; Granzymes/metabolism* ; Perforin/metabolism* ; Immunity, Innate ; Adult ; Lymphocytes/immunology*

OBJECTIVE: To explore the effect and mechanism of DNA methyltransferase 1 (DNMT1) knockout on the inhibition of acute myeloid leukemia (AML) by natural killer (NK) cells. METHODS: The peripheral blood NK cells of AML patients and controls were collected, and the mRNA and protein level of DNMT1 were measured by PCR and Western blot, respectively. The DNMT1 knockout mice were constructed to obtain NK^DNMT1-/- cells. The NK cells were stimulated with interleukin (IL)-12, IL-15, and IL-18 to construct memory NK cells, and then the interferon-γ (IFN-γ) levels were measured by ELISA. After co-culturing with memory NK cells and HL60 cells, the killing effect of NK^DNMT1-/- cells on HL60 cells was detected by LDH assay. Then, the HL60 cell apoptosis and NK cell NKG2D level were measured by flow cytometry. The perforin and granzyme B protein levels of NK cells were measured by Western blot. The AML model mice were constructed by injecting HL60 cells into the tail vein, meanwhile, memory NK cells were also injected, and then the mouse weights, CD33 positive rates, and survival time were detected. RESULTS: The mRNA and protein levels of DNMT1 in NK cells of AML patients were significantly higher than those in the control group (both P < 0.01), while the IFN-γ level induced by interleukin was significantly lower than that in the control group (P < 0.05). Compared with NK^DNMT1+/+ cells, the ability of NK^DNMT1-/- cells to secrete IFN-γ after interleukin stimulation was significantly increased (P < 0.05). The killing and apoptosis-inducing effects of NK^DNMT1-/- cells on HL60 cells were significantly stronger than those of NK^DNMT1+/+ cells (both P < 0.05). The NKG2D level and expression of perforin and granzyme B of NK^DNMT1-/- cells were significantly increased compared with NK^DNMT1+/+ cells (all P < 0.05). Compared with AML mice injected with NK^DNMT1+/+ cells, AML mice injected with NK^DNMT1-/- cells showed significantly increased body weight, decreased CD33 positive rate, and prolonged survival time (all P < 0.05). CONCLUSION Knocking out DNMT1 can enhance the inhibitory effect of NK cells on AML, which may be related to enhancing NK cell memory function.
Killer Cells, Natural/metabolism* ; Animals ; Leukemia, Myeloid, Acute ; Humans ; DNA (Cytosine-5-)-Methyltransferase 1 ; Mice ; Mice, Knockout ; HL-60 Cells ; Apoptosis ; Interferon-gamma/metabolism* ; Granzymes/metabolism* ; Perforin/metabolism* ; NK Cell Lectin-Like Receptor Subfamily K/metabolism*

Objective This study aims to construct and identify the chimeric antigen receptor NK92 (CAR-NK92) cells targeting NKG2D ligand (NKG2DL) (secreting IL-15Ra-IL-15) and verify the killing activity of NKG2D CAR-NK92 cells against multiple myeloma cells. Methods The extracellular segment of NKG2D was employed to connect 4-1BB and CD3Z, as well as IL-15Ra-IL-15 sequence to obtain a CAR expression framework. The lentivirus was packaged and transduced into NK92 cells to obtain NKG2D CAR-NK92 cells. The proliferation of NKG2D CAR-NK92 cells was detected by CCK-8 assay, IL-15Ra secretion was detected by ELISA and killing efficiency was detected by lactate dehydrogenase (LDH) assay. The molecular markers of NKp30, NKp44, NKp46, the ratio of apoptotic cell population, CD107a, and the secretion level of granzyme B and perforin were detected using flow cytometry. In addition, the cytotoxic mechanism of NKG2D CAR-NK92 cells on the tumor was verified by measuring the degranulation ability. Moreover, after NKG2D antibody inhibited effector cells and histamine inhibited tumor cells, LDH assay was utilized to detect the effect on cell-killing efficiency. Finally, the multiple myeloma tumor xenograft model was constructed to verify its anti-tumor activity in vivo. Results Lentiviral transduction significantly increased NKG2D expression in NK92 cells. Compared with NK92 cells, the proliferation ability of NKG2D CAR-NK92 cells was weaker. The early apoptotic cell population of NKG2D CAR-NK92 cells was less, and NKG2D CAR-NK92 cells had stronger cytotoxicity to multiple myeloma cells. Additionally, IL-15Ra secretion could be detected in its culture supernatant. NKp44 protein expression in NKG2D CAR-NK92 cells was clearly increased, demonstrating an enhanced activation level. Inhibition test revealed that the cytotoxicity of CAR-NK92 cells to MHC-I chain-related protein A (MICA) and MICB-positive tumor cells was more dependent on the interaction between NKG2D CAR and NKG2DL. After stimulating NKG2D CAR-NK92 cells with tumor cells, granzyme B and perforin expression increased, and NK cells obviously upregulated CD107α. Furthermore, multiple myeloma tumor xenograft model revealed that the tumors of mice treated with NKG2D CAR-NK92 cells were significantly reduced, and the cell therapy did not sensibly affect the weight of the mice. Conclusion A type of CAR-NK92 cell targeting NKG2DL (secreting IL-15Ra-IL-15) is successfully constructed, indicating the effective killing of multiple myeloid cells.
Humans ; Mice ; Animals ; Receptors, Chimeric Antigen/genetics* ; Interleukin-15 ; NK Cell Lectin-Like Receptor Subfamily K/metabolism* ; Granzymes ; Cell Line, Tumor ; Multiple Myeloma/therapy* ; Perforin

OBJECTIVE: To investigate the regulatory effect of interferon-α (IFN-α) on the apoptosis and killing function of CD56^dimCD57⁺ natural killer (NK) cells in systemic lupus erythematosus (SLE) patients, and to explore the specific mechanism. METHODS: A total of sixty-four newly treated SLE patients and sixteen healthy controls (HC) enrolled in the Second Hospital of Dalian Medical University were selected as the research subjects. And the gene expression levels of molecules related to NK cell-killing function were detected by real-time quantitative polymerase chain reaction. CD56^dimCD57⁺ NK cells were co-cultured with the K562 cells, and the apoptotic K562 cells were labeled with Annexin-Ⅴ and 7-amino-actinomycin D. Peripheral blood mononuclear cells were treated with 20, 40, and 80 μmol/L hydrogen peroxide (H₂O₂), and treated without H₂O₂ as control, the expression level of perforin (PRF) was detected by flow cytometry. The concentration of IFN-α in serum was determined by enzyme linked immunosorbent assay. The expression levels of IFN-α receptors (IFNAR) on the surface of CD56^dimCD57⁺ NK cells were detected by flow cytometry, and were represented by mean fluorescence intensity (MFI). CD56^dimCD57⁺ NK cells were treated with 1 000 U/mL IFN-α for 24, 48 and 72 h, and no IFN-α treatment was used as the control, the apoptosis and the expression levels of mitochondrial reactive oxygen species (mtROS) were measured by flow cytometry and represented by MFI. RESULTS: Compared with HC(n=3), the expression levels of PRF1 gene in peripheral blood NK cells of the SLE patients (n=3) were decreased (1.24±0.41 vs. 0.57±0.12, P=0.05). Compared with HC(n=5), the ability of peripheral blood CD56^dimCD57⁺ NK cells in the SLE patients (n=5) to kill K562 cells was significantly decreased (58.61%±10.60% vs. 36.74%±6.27%, P < 0.01). Compared with the control (n=5, 97.51%±1.67%), different concentrations of H₂O₂ treatment significantly down-regulated the PRF expression levels of CD56^dimCD57⁺ NK cells in a dose-dependent manner, the 20 μmol/L H₂O₂ PRF was 83.23%±8.48% (n=5, P < 0.05), the 40 μmol/L H₂O₂ PRF was 79.53%±8.56% (n=5, P < 0.01), the 80 μmol/L H₂O₂ PRF was 76.67%±7.16% (n=5, P < 0.01). Compared to HC (n=16), the serum IFN-α levels were significantly increased in the SLE patients (n=45) with moderate to high systemic lupus erythematosus disease activity index (SLEDAI≥10) [(55.07±50.36) ng/L vs. (328.2±276.3) ng/L, P < 0.001]. Meanwhile, compared with HC (n=6), IFNAR1 expression in peripheral blood CD56^dimCD57⁺ NK cells of the SLE patients (n=6) were increased (MFI: 292.7±91.9 vs. 483.2±160.3, P < 0.05), and compared with HC (n=6), IFNAR2 expression in peripheral blood CD56^dimCD57⁺ NK cells of the SLE patients (n=7) were increased (MFI: 643.5±113.7 vs. 919.0±246.9, P < 0.05). Compared with control (n=6), the stimulation of IFN-α (n=6) significantly promoted the apoptosis of CD56^dimCD57⁺ NK cells (20.48%±7.01% vs. 37.82%±5.84%, P < 0.05). In addition, compared with the control (n=4, MFI: 1 049±174.5), stimulation of CD56^dimCD57⁺ NK cells with IFN-α at different times significantly promoted the production of mtROS in a time-dependent manner, 48 h MFI was 3 437±1 472 (n=4, P < 0.05), 72 h MFI was 6 495±1 089 (n=4, P < 0.000 1), but there was no significant difference at 24 h of stimulation. CONCLUSION High serum IFN-α level in SLE patients may induce apoptosis by promoting mtROS production and inhibit perforin expression, which can down-regulate CD56^dimCD57⁺ NK killing function.
Humans ; Interferon-alpha/metabolism* ; Perforin/metabolism* ; Leukocytes, Mononuclear/metabolism* ; Hydrogen Peroxide/metabolism* ; Interferon-gamma/metabolism* ; CD56 Antigen/metabolism* ; Killer Cells, Natural/metabolism* ; Lupus Erythematosus, Systemic

OBJECTIVE: To analyze the gene polymorphisms of patients with lymphoma-associated hemophagocytic syndrome in Longyan area, Fujian province. METHODS: A total of 125 patients with lymphoma-associated hemophagocytic syndrome in Longyan, Fujian province, admitted to Longyan First Hospital from May 2017 to November 2020 were selected. Peripheral venous blood was collected from all the patients, and the genotypes of perforin 1 (PRF1) and interleukin-10 (IL-10) gene loci were detected by PCR-fluorescence probe method, and the correlation between PRF1 and IL-10 gene polymorphisms and lymphoma-associated hemophagocytic syndrome was analyzed. RESULTS: The mutation frequencies of PRF1 gene loci rs885821 (C>T), rs885822 (C>T), rs1889490 (G>A) in patients with lymphoma-associated hemophagocytic syndrome were 10.40%, 78.8% and 64.4%, respectively. The mutation frequencies of rs1800872 (A>C), rs1800871 (C>T) and rs1800896 (G>A) of IL-10 loci were 56.0%, 45.2% and 77.6%, respectively. CONCLUSION PRF1 and IL-10 gene loci were polymorphic in patients with lymphoma-associated hemophagocytic syndrome in Longyan area, Fujian province. Alleles C and G of PRF1 and IL-10 were risk factors, and alleles T and A were protective factors.
Humans ; Genotype ; Interleukin-10/genetics* ; Lymphohistiocytosis, Hemophagocytic/genetics* ; Lymphoma/genetics* ; Perforin/genetics* ; Polymorphism, Genetic

OBJECTIVE: To explore the synergistic immunomodulatory mechanism of interferon alpha-1b, interleukin-2 and thalidomide (ITI) regimen on patients with acute myeloid leukemia (AML). METHODS: Sixty eight untreated de novo or relapsed or refractory or maintenance therapy patients with AML admitted in the Affiliated Cancer Hospital of Zhengzhou University and the other 11 medical units from March 2016 to May 2019 were treated with ITI regimen. Peripheral blood specimen per patient was collected into EDTA-K3 anticoagulation vacuum tube before the administration of ITI and 3 months after the treatment; peripheral blood lymphocyte subsets and perforin and Granzyme B expression were analyzed by using flow cytometry; the levels of VEGF, IFN-γ, TNF-α and IL-6 in the plasma were detected by using a cytometric bead array. Thirty-five healthy subjects from the hospital physical examination centre were selected as normal controls. RESULTS: The ratio of CD4 CONCLUSION The ITI regimen can raise the ratio of CD4
CD8-Positive T-Lymphocytes ; Humans ; Interferon-alpha ; Interleukin-2 ; Leukemia, Myeloid, Acute/drug therapy* ; Perforin ; Thalidomide

OBJECTIVE: To detect genetic mutations in a child with late-onset hemophagocytic lymphohistiocytosis (HLH). METHODS: Clinical data of an 8-year-5-month-old girl with recurrent HLH and severe central nervous system disease was analyzed. Next-generation sequencing was used to detect mutation in the exons and adjacent introns of 17 genes associated with HLH. Suspected mutations were confirmed by Sanger sequencing. Influence of mutations on protein function was predicted with SIFT and PolyPhen-2 software. RESULTS: The child was found to carry compound heterozygous mutations of the PRF1 gene. Among these, the c.1349C>T (p.Thr450Met) mutation, with a SIFT predictive value of -4.921 (Deleterious variant) and a PolyPhen-2 predictive value of 1.000 (Probably damaging), was inherited from her father and known to be pathogenic. The c.1273dupT (p.Trp425fsX457) mutation was inherited from her mother and previously unreported, which resulted in the deletion of almost the entire C2 domain (amino acid residues 413 to 540) and carboxyl terminal of perforin, which seriously affected the function of the protein. CONCLUSION The c.1349C>T (p.Thr450Met) and c.1273 dupT (p.Trp425fsX457) compound heterozygous mutations of the PRF1 gene probably underlie the disease in this patient.
Central Nervous System Diseases ; Child ; Exons ; Female ; Humans ; Lymphohistiocytosis, Hemophagocytic ; Mutation ; Perforin

Objective: To investigate the expressions of growth arrest-specific protein (GAS1), IL-1 receptor accessory protein (IL-1RAP) and perforin (PRF1) in patients with anaplastic lymphoma kinase positive, anaplastic large cell lymphoma (ALK⁺ ALCL) and their relationships with clinical significances and the prognoses of ALK⁺ ALCL. Methods: Twenty-six formalin-fixed paraffin-embedded (FFPE) samples of ALK⁺ ALCL patients who were diagnosed from January 2011 to September 2016 were collected. Twelve FFPE samples of patients with ALK⁺ALCL, 13 FFPE samples of patients with peripheral T cell lymphoma (not otherwise specified) (PTCL-NOS) and 8 FFPE samples of patients with angioimmunoblastic T-cell lymphoma (AITL) were used as control groups. RQ-PCR and immunohisto-chemical staining were used to detect the mRNA and protein expressions of GAS1, IL-1RAP and PRF1. The clinical data were analyzed. Results: ①The expression levels of GAS1, IL-1RAP and PRF1 gene and protein in ALK⁺ ALCL group were higher than those of the control groups (P<0.05), but the expression levels had no statistically significant differences between the control groups (P>0.05). ②Patients with elevated lactate dehydrogenase (LDH) (0.77 vs 1.38, z=-3.292, P=0.001) or International prognostic index (IPI)≥3(0.62 vs 1.29, z=-2.495, P=0.013) had lower expression level of GAS1. Patients with stage Ⅲ/Ⅳ disease (0.89 vs 1.18, z=-2.212, P=0.027) or IPI≥3 (0.48 vs 1.13, z=-2.008, P=0.045) had lower expression level of PRF1. IL-1RAP expression level was not associated with clinical features. ③ALK⁺ ALCL patients in complete remission (CR) group had higher expression levels of GAS1 and PRF1 than patients in non-remission (NR) group (P values were 0.016 and 0.009). ④Kaplan-Meier survival analysis showed that patients with high expression levels of GAS1 and PRF1 had longer median overall survival and progression-free survival than patients with low expression levels of GAS1 and PRF1. Conclusion: GAS1, IL-1RAP and PRF1 could be molecular markers for ALK⁺ ALCL patients. They have potential diagnostic value and can be used for differential diagnosis in some difficult cases. ALK⁺ ALCL patients with high expression levels of GAS1 or PRF1 have better curative effects and prognoses.
Anaplastic Lymphoma Kinase ; Cell Cycle Proteins ; GPI-Linked Proteins ; Humans ; Lymphoma, Large-Cell, Anaplastic ; Perforin ; Protein-Tyrosine Kinases ; Receptor Protein-Tyrosine Kinases ; Receptors, Interleukin-1